Rensselaer has patented a device that listens to blood flowing in a patient's carotid artery and tells a doctor immediately if the artery is blocked by dangerous cholesterol deposits. The device provides an inexpensive, non- invasive screening system that doctors can use in their offices during routine checkups.
Michael Savic, professor of electrical, computer, and systems engineering, has built a working prototype for Sunward Electronics of Delmar, N.Y., which has been granted a license to market the technology.
The two large carotid arteries in the neck carry blood to the brain. Physicians now diagnose stenosis -- cholesterol deposits in the arteries -- by using expensive diagnostic devices or by listening to the sounds made by the blood.
When the heart pumps blood, velocity is high (systolic cycle) and the flow is turbulent even with no stenosis. If the artery is clean, there is no turbulence when the heart does not pump (diastolic cycle), and when the velocity of blood is low. But when cholesterol deposits are present, the flow is turbulent during both cycles of a heartbeat. An expert can hear the difference.
Savic has developed a number of computer systems that recognize highly specialized sounds, including a burglar alarm that reacts to the sound of breaking glass and a detection system that warns if gas is leaking from pipelines or storage tanks. He suggested that a similar device could distinguish differences in sounds produced by blood in patients with cholesterol problems. The system he developed was tested on patients, producing highly accurate readings.